The PokeCenters and PokeShops are scattered about the world as you travel. More often you will find the PokeShops within towns. You can use PokeDollars which you win from besting trainers or doing quests to purchase valuable items for you and your pixelated creatures.

Gyms are structures that will often spawn on the outskirts of a town. The Gym is a challenge for players and their teams to face off against that Gym's leader. Should the player succeed they will be awarded with a Gym Badge. These are handy and will be used much later in the game. 
